The E23K Polymorphism of KCNJ11 and Diabetic Retinopathy in Northern Iran.

Background: Diabetic Retinopathy (DR) is one of the most severe micro-vascular complications of diabetes mellitus (DM), involving interactions between environmental and genetic risk factors. KCNJ11 gene has a key role in insulin secretion and is of substantial interest in various populations. Methods: A population-based association of 524 T2DM patients was performed to delineate the genetic influence of KCNJ11 polymorphisms (rs5219, c.67A>G or E23K) on the risk of DR in an Iranian population. Genotyping was performed using TaqMan assay. Univariate and MLR analysis controlling for confounders was conducted to evaluate the association between rs5219 and DR. Results: No significant difference was observed in either genotypes distribution (p = 0.83) or allele frequency (p = 0.66) between T2DM individuals with and without DR in any models of inheritance. Genotype-phenotype association showed that DR group carrying GA genotypes, a significantly higher mean age was observed compared with two other genotypes (p = 0.04). MLR analysis indicated that HbAlc with adjusted OR of 1.84 (95% CI, 1.46-2.33, p = 0.00) and first-degree relatives of family history with adjusted OR of 2.85 (95% CI, 1.45-5.58, p = 0.002) were significantly associated with DR, but the c.67A>G genotype is not an independent predictor of retinopathy. Conclusion: Collectively, rs5219 was not associated with DR among Iranians with T2DM.